01 ranger showing ground in fuse panels


87linclsc

New member
Joined
May 28, 2020
Messages
5
Reaction score
0
Points
1
Location
NJ
Vehicle Year
2001
Make / Model
Ford Ranger
Transmission
Automatic
I've never been very good with electrical. The noticable symptoms are... no radio, no right front side running light, no left front turn signal, and the blower motor is intermittent. All these problems, with exception of the marker light started at the same time a couple weeks ago.

Ive checked the fuses and the only one that was blown was the 20 amp fuse in 29 (radio) in the interior. I replaced it and the radio worked until i turned the ignition off. It's still hot & hasn't blown again. So I've used a probe on the panels in the cab and under the hood and decided i should get a new probe because i couldn't believe what it was showing...

Here's what i got showing connection to ground. The rest are hot...

With the motor running

Interior panel:
3, 7, 24, 28, 33
Engine bay: 30, 43 (both of these show hot when the headlights, which work fine, are on)

With the motor off

Interior panel:
2, 3, 7, 14, 16, 19, 20, 33
24 & 28 show nothing
Engine bay: 44, 30 & 43 (same as running)

What's throwing me off is none of them are blowing... the truck is almost 20 yrs old and has 170k on it, so i can accept the blower motor being unrelated. I've checked all exposed wiring, short of pulling the dash... no breaks. I'm sorry if this is on here already, but I've searched all over. Before i start pulling the truck apart i figured I'd see if it was something stupid like my fuse block being bad or something.

Thanks
 


Rock Auto 5% Discount Code: 32B05A80BF19AF Expires: July 1st, 2020

87linclsc

New member
Joined
May 28, 2020
Messages
5
Reaction score
0
Points
1
Location
NJ
Vehicle Year
2001
Make / Model
Ford Ranger
Transmission
Automatic
Sorry, it's an 01, extended cab, 4.0, auto, 4x4. I put in an aftermarket head unit, speakers, & sub about 4 months ago. No issues until a couple weeks ago.
 

snoranger

Forum Staff Member
Forum Moderator
Supporting Member
ASE Certified Tech
Joined
Nov 25, 2007
Messages
7,058
Reaction score
3,130
Points
113
Location
Jackson, NJ
Vehicle Year
'79,'94,'02,'17
Make / Model
All Fords
My credo
I didn't ask for your life story, just answer the question!
It’s not unusual to see ground on a circuit that isn’t powered at the time.
Look at a simple light circuit:

Battery + —— fuse ———— bulb ————— battery -

If you remove the battery + , you will see battery- at the fuse because it’s still attached to bat- through the bulb.
 

adsm08

Senior Master Grease Monkey
Supporting Member
Article Contributor
Ford Technician
TRS 20th Anniversary
Joined
Sep 20, 2009
Messages
33,287
Reaction score
2,498
Points
113
Location
Dillsburg PA
Vehicle Year
1987
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0
Transmission
Manual
2WD / 4WD
4WD
Tire Size
31X10.50X15
When you see a ground connection on a dumb light or a PowerProbe (especially a PowerProbe) at a fuse it is because the probe is sensitive enough to see the ground connection through the component the fuse powers, if the circuit is not turned on.

Ford uses switched powers and fuses go between switches and loads, so with the switch in the off position the entire circuit between the fuse and the ground is still hooked up. This is why your probe is showing ground at the fuse. Things turning off is also why you have more of them with the engine off.
 

87linclsc

New member
Joined
May 28, 2020
Messages
5
Reaction score
0
Points
1
Location
NJ
Vehicle Year
2001
Make / Model
Ford Ranger
Transmission
Automatic
Ok... with the radio harness unplugged, the constant feed is showing ground, not hot. Do i treat it like a fault and chase it down? Why isn't it causing a drain? Why isn't the fuse blowing? It is the correct size fuse. How do i proceed from here?
 

Uncle Gump

Forum Staff Member
Forum Moderator
Supporting Member
Joined
Sep 17, 2018
Messages
4,162
Reaction score
2,465
Points
113
Location
Plano IL
Vehicle Year
2006
Make / Model
Ford
Engine Size
4.0L
Transmission
Automatic
2WD / 4WD
4WD
My credo
Lead, Follow or get out of my way
Do you have wire schematics for the truck?

If not... you should invest.

The Tech Library has some radio schematics for a 2001 you can have a look at...

 

ericbphoto

Old Redneck just wingin' it.
Forum Moderator
Supporting Member
U.S. Military - Veteran
TRS 20th Anniversary
Joined
Feb 7, 2016
Messages
5,352
Reaction score
2,657
Points
113
Age
55
Location
Wellford, SC
Vehicle Year
1993
Make / Model
Ford Ranger
Engine Type
3.0 V6
Engine Size
3.0L
Transmission
Manual
2WD / 4WD
4WD
Total Lift
6"
Tire Size
35"
My credo
In theory, theory and practice are the same. In practice, they are different.
Ok... with the radio harness unplugged, the constant feed is showing ground, not hot. Do i treat it like a fault and chase it down? Why isn't it causing a drain? Why isn't the fuse blowing? It is the correct size fuse. How do i proceed from here?
Does it truly have continuity to ground? Or is it just not powered? There is a difference.

Either way, if you are really looking at the constant feed, it should have battery voltage. If not, then yes there is a problem that must be found and corrected.
 


Top